Stabilized halogenated hydrocarbon toxicant compositions



United States Patent M rm. c1. A01n 9/34, 9/00, 9/32 U.S. Cl. 71-109 6 Claims ABSTRACT OF THE DISCLOSURE Toxicant compositions of improved stability particularly suitable for combating pests, bacteria and parasites, e.g., insecticidal, herbicidal, fungicidal, rodenticidal, disinfectant, and germicidal compositions, comprise:

(1) a halogenated hydrocarbon toxicant; (2) a hydrocarbon solvent; and (3) a stabilizer comprising certain fractions of complex carboxylic acids or their monomeric esters derived from complex sulfur-containing aromatic compounds of petroleum origin, i.e., solvent extracts obtained in the solvent refining of mineral lubricating oils and related sulfur containing starting materials such as hydrogenated solvents, extracts, FCC recycle stock and decant oil. The acids are prepared by metalation of said aromatic compounds to form the adduct, carbonation of the adduct to form the salt of the corresponding mixed mono-, diand polycarboxylic acids, acidification of the salt mixture to form the free acids, and fractionation of the acid mixture to obtain acids which are predominantly monocarboxylic in nature.

This application is a divisional of our copending application, Ser. No. 219,785, filed Aug. 27, 1962, now U.S. Pat. 3,277,014, issued Oct. 4, 1966.

This invention is based on the discovery that the complex monocarboxylic acids, or fractions containing not less than about 80% by weight of monocarboxylic acids and/ or the monomeric esters of said monocarboxylic acids or fractions, prepared from certain sulfur-containing starting materials of petroleum origin as hereinafter more definitely defined, quite unexpectedly stabilize hydrocarbon solvent solutions of halogenated hydrocarbon toxicants, such as DDT, and prevent or delay the precipitation of the toxicants from the solvent for length of time sufficient for commercial application. Furthermore we have found that the herein defined selected fraction of complex carboxylic acids or their monomeric esters or mixtures of the acids and esters are more effective as stabilizers for halogenated hydrocarbon toxicants in hydrocarbon solvent solutions than certain of the known prior art stabilizers. In addition, the stabilizers of this invention are effective at lower concentrations than the known prior art stabilizers and do not have the deleterious side effects which are characteristic of some of the prior art stabilizers now in use.

The number of organic toxicant compositions now in use for household, industrial and agricultural purposes is increasing. Many of the biocides or toxicants used are water-insoluble, and accordingly are prepared in concentrated solutions in other solvents for emulsification with water at the time of application. Halogenated hydrocarbon toxicants, such as chlorinated hydrocarbons like DDT, are prepared and shipped in concentrated hydrocarbon solvent solutions and diluted or emulsified for 3,511,638 Patented May 12, 1970 the end use. In preparing such emulsions or solutions, various types of surface active and detergent agents are used to aid in holding the toxicant in solution and enhancing its usefulness. However, throughout this art there is the constant problem of the stability of the concentrated hydrocarbon solution of the concentrate, and, although certain stabilizers are known and used, their ability to enhance the stability, postpone precipitation of the toxicant, and readily form dilute aqueous emulsions is varied and subject to a number of limitations, known to those skilled in this art.

According to the prior art, a halogenated hydrocarbon toxicant, such as DDT (dichlorodiphenyltrichloroethane) is applied as a solution or emulsion of low concentrations, i.e., about 5% by weight (Muller, U.S. Patent 2,329,074, now Re. 22,700; Siegler, U.S. Patent 2,358,942). For purposes of storage and transportation, such a toxicant is prepared in more concentrated solutions in a hydrocarbon solvent, generally a saturated solution, for economic reasons. However, because of the diverse nature of the toxicants, differences in the properties of the stabilizers, and differences in solubilities, compatibilities and environments, the selection of the proper stabilizer is empirical, and the problem of concentrate stability during handling, shipping and storage persists because the selected stabilizers of the prior art have limited application or lack versatility.

This is a particularly troublesome problem when handling or shipping hydrocarbon concentrates of DDT and related halogenated hydrocarbon toxicants. Although a gas oil, for example, will dissolve 25 to 30% by Weight of DDT at room temperature, the solution is unstable and deteriorates at lower temperatures during storage, handling or shipping in the winter months. Under these conditions, the DDT slowly precipitates, generally over relatively extended periods of time, depending on the severity of the cold, and unfortunately, this precipitate does not readily redissolve when the concentrate is warmed to normal temperatures. Peculiarly, the DDT precipitates in excess of the quantity required toform a saturated solution at the lowered temperature and a large quantity of DDT is not precipitated as soon as the saturation temperature is passed or even after seeding by initial crystal formation occurs. The precipitation and deterioration of the concentrate is slow and substantially continuous over a period of many hours.

Such well-known compounds as stearic acid, palmitic acid, lower fatty acids and the proprietary compositions, Parafiow and Santapour do not offer sufficient protection from this deterioration of the concentrates. Other products reduce the effectiveness of the toxicant or have deleterious side effects on plant foliage and the skin. By using the complex monocarboxylic acids and/or their monomeric esters or partial esters, described herein, in amounts ranging from about 0.5 to 10% by Weight, as stabilizers or emulsifiers, the foregoing difficulties are mitigated or eliminated.

Accordingly, it becomes a primary object of this invention to provide stable toxicant compositions containing halogenated hydrocarbon toxicants dissolved in a hydrocarbon vehicle and containing a stabilizing amount of certain complex monocarboxylic acids, or their monomeric esters, derived from solvent extracts obtained in the solvent refining of mineral lubricating oils and related sulfur-containing starting materials by metalation, carbonation, acidificaton and fractionation.

An object of this invention is to provide stable toxicant compositions containing halogenated hydrocarbon toxicants, a hydrocarbon vehicle, and between about 0.5 to 10% by weight of selected fractions of complex carboxylic acids and/or the monomeric esters thereof as herein more particularly defined.

Another object of this invention is to provide stable toxicant compositions containing chlorinated hydrocarbon toxicants, a hydrocarbon vehicle, and between about 0.5 to 10% by weight of complex monocarboxylic and/ or dicarboxylic acids derived from sulfur-containing aromatic hydrocarbons of petroleum origin.

Another object of this invention is to provide stable toxicant compositions containing chlorinated hydrocarbon toxicants, a hydrocarbon vehicle, and between about 0.5 to 10% by weight of monomeric esters of complex monocarboxylic and/or dicarboxylic acids derived from sulfur-containing aromatic hydrocarbons of petroleum origin.

Still another object of this invention is to provide concentrated solutions of DDT in hydrocarbon solvents which are stabilized against precipitation by the incorporation of effective amounts of certain fractions of complex carboxylic acids, or monomeric esters of said carboxylic acids, derived from solvent extracts obtained in the solvent extraction of mineral lubricating oils, using a solvent selective for aromatic compounds, or derived from hydrogenated solvent extracts or from FCC recycle stock.

A feature of this invention is the discovery that the incorporation of the stabilizers disclosed herein with a hydrocarbon solvent forms a stable emulsifier composition for toxicants.

These and other objects of this invention will be described or become apparent as the specification proceeds.

THE TOXICANTS The toxicants used in the compositions of this invention have the formula where X represents a halogen that is chlorine, bromine, or iodine, or mixtures of same, and Y and Z each represent a radical of the group consisting of monovalent aliphatic, aryl, and aralkyl radicals of the benzene series. Examples of aliphatic or alkyl radicals coming within the foregoing definition are those containing 1 to 20 carbon atoms, that is, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, amyl, isoamyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyi, hexadecyl, heptadecyl, octadecyl, nonadecyl and eicosyl. Examples of aryl radicals are phenyl, naphthyl and anthryl radicals, and the aralkyl radicals may be combinations of the foregoing defined aryl and alkyl radicals.

The best-known species coming within this definition is dichlorodiphenyltrichloroethane (commonly referred to as DDT). Other examples of toxicants coming within the formula or within the definition of toxicants that can be used in accordance with this invention are: (bis(methoxyphenyl)trichloroethane) dichlorodiphenyldichloroethane; benzenehcxachloride; 1,2,4,5,6,7,8-octachloro-4,7-methano-3a, 4,7,7a-tetrahydroindane, known commercially as Chlordane; polychlorobicyclicterpenes; the gamma isomer of 1,2,3,4,5,6-hexachlorocyclohexane, known commercially as Lindane; 1,2,3,4,l0,l-hexachloro-1,4,4a-5,8,8a-hexahydro 1,4,5,8 dimethanenaphthalene, known commercially as Aldrin; l,2,3,4,10,10-hexachloro 6,7-epoxy 1,4,4a,5,6,7,8,8a-octahydr0-1,4,5,8-dimethanenaphthalene, known commercially as Dieldrin; and 1,1,1-trichloro 2,2 bis(p methoxyphenyl)-ethane, known commercially as Methoxychlor; the following herbicides: (2,4-dichlorophenoxy)acetic acid and its derivatives such as the esters and salts, known commercially as 2,4-D; (2,4,5-trichlorophenoxy)acetic acid and its derivatives such as the esters and salts, known commerically as 2,4,5-T; and N-(trichloromethylmercapto) phthalimide; the fungicides: bis(dimethylthiocarbonyl) disulfide and pentachlorophenol; and the germicide cetyl trimethyl ammonium bromide.

The invention is intended to include diphenyl haloethanes, which possess insecticidal properties, and includes ethanes having two or three chlorine or bromine atoms on one of the ethane carbon atoms. The other ethane carbon atom carries two phenyl groups which may be unsubstituted or substituted and may be alike or different. Typical diphenyl haloethanes are 1, l l -trichloro-2,2bis (chlorophenyl ethane; 1, l l-tribromo-2,2-bis (chlorophenyl ethane; 1, l l -trichloro-2,2-bis (fiuorophenyl ethane; 1,1, 1-trichlor0-2,2-bis(bromophenyl) ethane; 1, 1-dichloro-2,2-bis(bromophenyl) ethane; l, 1-dichloro-2,2-bis (chlorophenyl ethane; 1-1-dichloro-2,2-bis (fiuorophenyl ethane; 1,1,l-trich1oro-2,2-bis(chlorotolyl) ethane; 1,1,1-trichloro-2,2-diphenylethane; 1,1, 1-trichloro-2,Z-ditolylethane; 1,l,1-trichloro-2,2-di(ethylphenyl ethane; 1,1-bis(acetylphenyl)-2,2,2-trichloroethane; 1, l-dichloro-2,Z-ditolylethane; 1, l-dichloro-2,2-di ethylphenyl) ethane; 1,1,1-trichloro-2-phenyl-2-chlorophenylethane;

1,1 ,1-trichloro-2-tolyl-2-chlorophenylethane; 1,1,l-tribromo-2,2-tolylethane; 1',1,1-trichloro-2,2-'bis(chloronitrophenyl )ethane; 1,1,1-trichloro-2,2-bis(methoxyphenyl)-ethane;

1, 1,l-tribromo-2,2-bis (methoxyphenyl) ethane;

1 ,1,l-trichloro-2,2-bis(ethoxyphenyl) ethane;

1,1 ,1-trichloro-2-chlorophenyl-2-methoxyphenylethane;

1, l-dichloro-Z-brom ophenyl-Z-methoxyphenylethane 1,1-thiocyanophenyl-2,2,2-trichloroethane, and the like.

The substituents of the phenyl rings may be in ortho, meta, or para positions. The actual materials of commerce usually consist of a mixture of isomers.

Any of the foregoing toxicants, particularly the halogenated hydrocarbon type, such as DDT and related compounds, in substantially saturated or supersaturated solution in a hydrocarbon or petroleum solvent, are stabilized without deleterious effects by incorporating about 0.5% to 10% by weight of fractions of the following described complex carboxylic acids, or the monomeric esters thereof as hereinafter defined.

THE COMPLEX ACID STABILIZERS The stabilizers used in this invention are prepared from mixtures of m0no-, di and polycarboxylic acids having from 1 to 7 carboxyl groups per molecule, resulting from reacting a sulfur-containing aromatic hydrocarbon of petroleum origin with an alkali metal to form the alkali metal adduct, reacting the alkali metal adduct with carbon dioxide under conditions to form the alkali metal salt of the corresponding carboxylic acids, acidifying the resulting complex salts to form the mixture of free carboxylic acids, and fractionating the mixture of acids to separate a fraction which is predominantly to monocarboxylic in nature, from the mixed monoand dicarboxylic, or predominantly dicarboxylic acids. Alternately the fractionation, as herein subsequently described, can be preformed using the alkali metal salt mixture.

The methods used in preparing the mixture of complex carboxylic acids, from which selected fractions are prepared for use in accordance with this invention, are described in detail in the following copending applications:

Ser. No., 819,932, filed June 12, 1959, T. W. Martinek, now abandoned; Ser. No. 79,661, filed Dec. 30, 1960, W. E. Kramer et al., now U.S. Pat. 3,153,087; Ser. No. 160,882, filed Dec. 20, 1961, T. W. Martinek, now U.S. Pat. 3,222,137.

The starting material for the metalation, carbonation and acidification reactions comprises sulfur-containing aromatic materials of the group consisting of solvent extracts obtained in the solvent extraction of mineral lubricating oils by treatment with a solvent selective for aromatic compounds, hydrogenated solvent extracts or otherwise refined solvent extracts, FCC recycle stock, and decant oil from FCC processes and mixtures of these source materials. Of these starting materials, the solvent extracts and the hydrogenated solvent extracts are preferred. These materials result from the treatment of mineral lubricating oils with a solvent selective for aromatic materials for the purpose of separating non-aromatic hydrocarbons (the raffinate and finished oil) from the aromatic hydrocarbons (the extract or waste product).

The final process of refining mineral lubricating oils by means of solvent extraction to produce the rafiinate finished oil and the solvent extract waste product is well known and described in detail in the foregoing copending applications. In addition, these copending applications set forth in detail the physical and chemical characteristics of a large number of specific solvent extracts from different sources, using different solvents, that may be used as a starting material. Accordingly, for purposes of this invention, it is only necessary to describe and disclose the final physical and chemical properties of these materials.

In general, solvent extracts and hydrogenated solvent extracts have the characteristics set forth in Table I.

TABLE I Characteristics of solvent extract starting materials Characteristic: Range of value Gravity, API 7.318.3 Gravity, sp., 60/60 F. 09446-10195 Viscosity, SUS 210 F. 40-1500 Viscosity index 153-39 Pour point (max.), F. 20-115 Color NPA 2-5D Molecular wt., ave. (above 300) 320750 Sulfur, percent wt. 1.94.5 Aromatic compounds (incl. heterocyclics) 75-98 Av. No. of rings/mean arom. mol. 1.7-3.5

The most important chemical properties depended upon to define these materials and the complex carboxylic acids derived therefrom are the average molecular weight, the weight percent of sulfur and the average number of aromatic rings per mean aromatic molecule.

The complexity of the types of compounds present in solvent extracts which are carried into and characterize the carboxylic acids and esters derived therefrom, as based upon the analyses of several of the species of extracts described in detail in said copending applications, is illustrated by the following Table II.

TABLE II Estimated chemical composition of solvent extracts Type of compound: Approx. percent in the extract Saturated hydrocarbons 12.5 Mononuclear aromatics:

Substituted benzenes 25.0 Dinuclear aromatics:

Substituted naphthalenes 30.0 Trinuclear aromatics:

Substituted phenanthrenes 10.0

Substituted anthracenes 5.0

Tetranuclear aromatics:

Substituted chrysenes 00.5

Substituted benzphenanthrenes 0.2

Substituted pyrenes 0.2 Pentanuclear aromatics:

Perylene 0.01 Sulfur compounds oxygen compounds, etc. 16.5

1 Mainly heterocyclic compounds.

Any portion of the reactive aromatic constituents in solvent extracts or other sources may be isolated therefrom, to be used as starting materials for the metallation, carbonation and acidification reactions to prepare the complex carboxylic acids used in accordance with this invention. For example, solvent extracts may be distilled and selected fractions thereof used as the starting materials. The content of reactive, complex, polynuclear, aromatic compounds and heterocyclics present in solvent extracts, as illustrating the preferred source material, may vary depending on the type of solvent, the extraction process applied, and the mineral oil treated, although the general types of compounds present in the extract are not so varied. Extracts containing from about 30% to of polynuclear aromatics and heterocyclics of aromatic nature represent a preferred type of starting material for economic reasons.

In addition to the general physical and chemical properties of the solvent extracts given in Tables I, II and III, these starting materials may be further characterized by the fact that their boiling point (initial) is between 300 to 1000 F., the end-boiling-point is between 400 and 1210 F., and they may exhibit pour points as high as F. Chemically, the extracts may contain about 1.9 to 4.5% wt. of sulfur, present mainly as heterocyclic rings, and 0.01 to 0.% by wt. nitrogen and/or oxygen, also present in heterocyclic rings. On a volume basis, the extracts may contain from about 15% to 50% of sulfur compounds, and 30% to 90% of complex aromatic and thio compounds. Many of these characteristics, particularly the chemical characteristics, carry over into the complex carboxylic acids prepared therefrom.

The solvent extract starting material may be vacuumdistilled, dewaxed and/ or clay-contacted and/ or hydrogenated prior to use in preparing the complex carboxylic acids from which the selected fractions used in accordance with this invention are derived. Dewaxing can be accomplished by known methods, e.g., treatment with 45% MEK and 55% toluene as the dewaxing solvent, using temperatures in the order of 10 F., and solvent/ solvent extract ratios of about 8/ 1. This treatment results in a dewaxed extract which has a pour point of about -|-5 F., and results in the removal of about 2% wax having a melting point of about F. Clay-contacting can be accomplished by known methods.

The preparation of hydrogenated extracts is accomplished using known methods of hydrogenation, particularly mild hydrogenation; thus, a preferred method of preparing hydrogenated extracts is to hydrogenate the distillate lube oil or residual oil before the extraction by treatment with hydrogen at 100-500 p.s.i.g., using temperatures of 530-600 F., in the presence of a molybdena-silica-alurnina catalyst. This same method can be applied to the solvent extracts per se, that is, after their separation from the raflinate. Hydrogenation has been found to result in the decarboxylation of any naphthenic acids present and the production of an extract from which complex acids of enhanced properties can be obtained by metalation, carbonation, acidification and fractionation.

Other known methods of hydrogenation can be applied to the solvent extracts using such catalysts as Filtrol, cobalt-molybdate, silver-molybdate and Porocel. The characteristics of a representative hydrogenated, dewaxed, and clay-contacted solvent extract are: API, 9.5; Color, NPA, 7; Flash (COC), 420 E; Fire (COC), 465 F.; Pour point, 5 F.; Vis. 100 F., 1075 SUS; Vis. 210 F., 58.5 SUS; VI, 96; Neut. No. (1948), 0.05; Sulfur, 2.60 wt. percent and CR. percent, 0.01. The FCC recycle stock is illustrated by the 19% extract (phenol solvent) of FCC recycle stock, which extract had the following properties: API, 1.8; sulfur 1.9 wt. percent; Br. No., 17; RI (20 C.) 1.6372 and Engler Distillation, IBP=589 F.; 90%=745 F. The use of these latter starting materials is described in copending application Ser. No. 79,661. The preparation and properties of FCC recycle stock and decant oil are described in copending application Ser. No. 242,076 filed Dec. 4, 1962. The latter has a boiling range of about 375 to 995 F. and contains about 0.87 wt. percent sulfur.

The mixed complex carboxylic acids are prepared from the foregoing starting materials by reacting same with a sufiicient amount of, and preferably an excessive amount of a metal of Group I-A of the Periodic Chart of Atoms, Hubbard, 1941, that is, sodium, potassium, lithium, rubidium, or cesium, at a temperature of about 60 C. to 115 C., at atmospheric or superatmospheric pressures, and with a reaction solvent such as the dialkyl glycol ethers, dimethyl glycol ether, methyl alkyl ethers, dimethyl ether, tetrahydrofuran, dioxane, trimethylamine, methylal and mixtures thereof, to form the alkali metal adduct. This metalation reaction is sometimes diflicult to initiate and shearing, the preparation of a preformed dispersion of the alkali metal in the starting material, and the use of excess amounts of alkali metal, are some of the expedients described in said copending applications to increase the yield of acids by unit weight of alkali metal consumed. 1

Following the adduct formation, the reaction mixture (which is now colored violet to blue) is carbonated by reaction with gaseous or solid carbon dioxide at temperatures ranging from -50 C. to 115 C. This results in dissipation of the color and formation of the alkali metal salts of the corresponding mono-, diand poly-carboxylic acids. Further washing separates the water soluble salts from the solvent phase, and acidification with a mineral acid frees and precipitates the complex mixtures of acids.

This initial reaction product is illustrated by Examples I and II, experiments 1 through 21 of Table II in application Ser. No. 819,932, and is also illustrated by the Runs 12 through 47 described in application Ser. No. 79,661. Any of these mixtures of complex acids can be used as the source of monocarboxylic acids or their esters to be used as stabilizers in accordance with this invention. In order to further illustrate this source material, a number of specific examples are given, in Table III.

fractionation of the mixed acids is described in detail in the copending applications:

Ser. No. 161,355, filed Dec. 22, 1961, L. A. 100 et al., now U.S. Pat. No. 3,228,963; Ser. No. 209,741, filed July 13, 1962, L. A. Joe, now abandoned; Ser. No. 247,358, filed Dec. 26, 1962, L. A. Joo, now U.S. Pat. No. 3,250,- 786.

In accordance with application Ser. No. 161,355, fractions of the complex acids are separated in accordance with their acid numbers and the number of carboxyl groups per molecule by (1) dissolving the salts of the acids to be fractionated in a first solvent in which the free acids are at most only sparingly soluble; (2) adding a small amount of an acid sufficiently strong to liberate a portion of the desired acids; (3) extracting the liberated acids from the resulting mixture using a second solvent which is immiscible with said first solvent; (4) adding another small amount of mineral acid to the remaining salt solution; (5 again extracting the acids thus liberated with said solvent; and (6) continuing this cyclic acidification and extraction until the first solvent is substantially free of the desired acids and their salts. The process is illustrated as follows:

EXAMPLE I A water solution containing 26 g. of the sodium salts of extract acids" per 100 ml. was prepared, a 150-ml. portion of it was treated with 1 ml. of hydrochloric acid, and the resulting liberated acid was extracted with 20 ml. of toluene (Fraction 1, Table IV). Then the acidification With hydrochloric acid and the extraction were repeated in cyclic fashion, until no more acid was obtained from the water phase. After the extract acid had reached an acid number of 220 (Fraction 6, Table IV), the extraction solvent was changed to ether, since the higher-acid-number acids are insoluble in toluene. The results of the procedure are given in Table IV.

TABLE III.TYPICAL PROPERTIES OF MIXTURES OF COMPLEX CARBOXYLIO ACIDS DERIVED FROM SOLVENT EXTRAC'IS Acid value Mol wt.

Percent Percent S Br. No. Number:

unsap. Eq. wt.

Eqs. Acid mol. No.

Certain of the foregoing mixtures of acids are already predominantly monocarboxylic i.e. 80% or more or contain a mixture which predominates in the monoand di carboxylic acids with only small amounts of higher acids. This is illustrated by those acids having acid numbers in the order of 120 to 200, that is, acid sample numbers 38, 46, 51, and 101, which accordingly would not have to be fractionated prior to use in accordance with this invention.

The exclusion of those acids having two or more carboxyl groups per molecule, and having acid numbers above 200, and preferably above about 180, to form fractions having acid numbers in the range of about 100 to 200 and preferably 100-180, is accomplished by means of fractionation. The detailed procedures for carrying out the TABLE IV Original Extract Acid: A.N. 218; mol. wt. 420; percent unsap. 8.7 COOH/mo1. 1.66.

9 EXAMPLE II In this example, the same stock solution was used as in Example I, but ether was used as the extraction solvent from the beginning. First, ISO-ml. portion of the extract acid salt solution was extracted with 20 ml. of ether. Then 1 EXAMPLE 111 An 80.0 g. portion of the extract polybasic acids having an acid number of 214, a mol. wt. of 410, and containing 4.80% saponifiables was dissolved in 150 ml. of toluene, and 20 ml. aliquots of this solution were precipitated with 5 ml. of concentrated hydrochloric acid and ml. of different amounts of n-heptane. The resulting precipitates water were added to the ether solution, and the resulting were individually filtered, washed with n-heptane and acidic water phase was separated from the ether phase, dried. The solute remaining in each filtrate was recovered containing free extract acid, and combined with the by distilling off the mixed toluene-heptene solvent. The raftinate phase from the previous ether extraction step. 10 fractions so derived were characterized as follows:

TABLE VI Precipitate Filtrate Amount of Fraction n-heptane Acid M01. Acid Mol. No. used (mL) Grams No. wt. COOH/mo1. Grams No. wt. COOH/mol is as? After the water phases had been combined, they were Filtrate fraction numbers 1 through 6 and, particularly extracted again with ether, the ether solution was acidified filtrate fraction numbers 4, 5 and 6 of Table VI are illuswith 1 ml. of concentrated hydrochloric acid and 10 ml. trative species of predominantly monocarboxylic acids of water, and the water phase was again separated from to be used as stabilizers in accordance with this invention. the ether phase, again containing extract acid, and com- In accordance with application Ser. No. 247,358, sebined with the stock solution. This procedure was repeatlected fractions of the carboxylic acids are obtained by ed until no more acid was obtained from the extract-acid- (1) dissolving the complex mixture of acids to be fracsalt water solution when the solution was acidified. donated in an excess of aqueous caustic; (2) adding sat- The ether phases were washed twice with lO-ml. porurated salt solution and ether to effect a three phase septions of water, and then the ether was evaporated to leave aration; (3) separating the phases; and (4) separating the the acid fractions as products. These acid fractions had acids from each of the phases by individual acidification. higher acid numbers than the fractions obtained by the By this method a middle phase comprising an ether-water method used in Example I indicating that some acid salt solution of predominantly monocarboxylic complex acids, had been extracted along with the acids in Example I. useful in accordance with this invention, is obtained. The results of this method are given 1n Table V. EXAMPLE IV TABLE v A 2.17 g. portion of an extract polybasic acid was pul- Original Extract Acid: A.N. 218; mol. wt. 420; percent unsap. 8.7 -COOH/m0l. 1.66.

Fractions 1 through 5 of Table IV and fractions 1 through 10 of Table V are illustrative of species of substantially monocarboxylic acids that can be used in accordance with this invention.

The desired fractions of mixed complex carboxylic acids are prepared in accordance with application Ser. No. 209; 741 by (1) dissolving the free acid mixture to be fractionated in a first solvent in which the mixture is readily soluble; (2) adding a small amount of an aliphatic solvent to precipitate or liberate a portion of the desired acids; (3) filtering the liberated acids from the resulting mixture; (4) adding another small amount of said aliphatic solvent to the remaining acid mixture solution; (5) again filtering the acids thus liberated; and (6) continuing this cyclic precipitation and filtration until the solute consists primarily of monobasic acids and the desired di-, tri-, and tetracarboxylic acids have been separated. Illustrative examples from application Ser. No. 209,741 are given as follows:

verized and dissolved in 60 ml. of water containing 2.39 g. NaOH and 10 ml. ether. This mixture was poured into a separatory funnel containing 60 ml. additional ether, and shaken vigorously. Then, 10.2 ml. of saturated NaCl solution (containing 2.96 g. NaCl) was added, and the mixture was shaken vigorously for 2 minutes. After settling, a three-phase system emerged: a light-yellow, upper phase, consisting of unsaponifiables in ether; a darkbrown middle phase, consisting of sodium salts of monobasic acids (including naphthenic acids) dissolved in ether-water mixture; a lower phase containing a water solution of sodium salts of di-, triand higher polybasic acids. Then, the phases were separated and acidified separately with HCl, and the organic acids released were extracted with ether. Finally, each ether extract was dried, yielding the products in the tabulation below:

TABLE VII Fractional Products From From From upper middle lower Original Charge phase phase phase 8 Di-, Tri-, and higher polybasic acids.

EXAMPLE V A 13.43 g. portion of an extract polybasic acid was pulverized and dissolved in 250 ml. of water containing 9.45

ether-water mixture; a lower phase containing a water solution of sodium salts of di-, tri-, and higher polybasic acids. The phases were separated and acidified separately with HCl, and the organic acids released were extracted with ether. Each ether extract was dried, yielding the products described below:

TABLE VIII Fractional Products From From From upper middle lower Original Charge phase phase phase Wt. (g) "13. 43 0. 44 9. 21 3. 78 Percent of charge. 100 3. 3 68. 6 28.1 Acid No. of tree... 218 18 178 309 Equivalent wt.- 257 315 181 Appearance Essential composition l Dark brown color, crystalline.

2 Yellow color, soft solid.

3 Very dark brown, soft gum, product.

4 Amber color crystalline.

6 Mixture of Mono-, Di-, Tri-, and higher polybasrc acids. 6 Unsap, color bodies.

1 Monobasic acids (including naphthenic acids).

8 Dl-, Tri-, and higher polybasic acids.

EXAMPLE VI A 3.22 portion of extract polybasic acid was pulverized and dissolved in 100 ml. of water containing 3.3 g. of NaOH and 10 ml. of ether, this mixture was poured into a separatory funnel containing 100 ml. additional ether, and the funnel was shaken vigorously. Then, 20 ml. of saturated NaCl solution (containing 5.7 g. of NaCl) was added and the mixture was shaken vigorously for 2 minutes. After settling, a three phase system emerged: a light yellow upper phase consisting of unsaponifiables in ether; a dark brown middle phase consisting of sodium salts of monobasic acids (including naphthenic acids) dissolved in ether-water mixture; a lower phase containing a Water solution of sodium salts of di-, tri-, and higher polybasic acids. Each phase was separated and acidified separately with HCl, and the organic acids released were extracted with ether. Finally each ether extract was dried, yielding the products described below:

1 Dark brown color, crystalline.

1 Yellow, soft solid.

8 Very dark brown soft, gum product.

4 Amber color crystalline.

5 Mixture of mono-, di-, tri-, and higher polybasic acids. 6 Unsap. color bodies.

7 Monobasic acids (incl. naphthenic acids).

5 Di-, tri-, and higher poly-basic acids.

EXAMPLE VII An 0.84 g. portion of extract polybasic acid was pulverized and dissolved in 30 ml. of water containing 0.93 g. of NaOI-I and 5 ml. of ether, this mixture was poured into a separatory funnel containing 30 ml. additional ether, and the funnel was shaken vigorously. Then, 6 ml. of saturated NaCl solution (containing 1.7 g. of NaCl) was added, and the mixture was shaken vigorously for two minutes. After settling, a three-phase system emerged: a light yellow upper phase consisting of unsaponifiables in ether; a dark brown middle phase consisting of sodium salts of monobasic acids (including naphthenic acids) dissolved in ether-water mixture; a lower phase containing a water solution of sodium salts of di-, tri-, and higher polybasic acids, phases were separated and acidified individually with HCl, and the organic acids thus released were extracted with ether. Each ether extract was dried, yielding the products described below:

TABLE X Fractional Products From From From upper middle lower Original Charge phase phase phase Wt. (g.) 0.84 0.10 0.40 0.34 Percent of charge- 11. 9 47. 6 40. 5 Acid number 263 39 166 295 Equivalent weight 213 338 Appearance Essential composition- 1 Dark brown color, crystalline.

2 Yellow color.

3 Very dark brown; soft, gum product.

4 Amber color crystalline.

5 Mixture of di-, triand higher polybasic acids and unsaponifiables. Unsap. and color bodies.

7 Monobasic acids, incl. naphthenic acids.

8 Di-, tri-, and higher polybasic acids.

EXAMPLE VIII A 6.1 g. portion of extract polybasic acid, having an acid number of 206, was dissolved in 200 ml. of tetrahydrofuran and neutralized with a calculated amount of sodium hydroxide (0.89 g.) in 200 ml. of water. There was no separation of phases. Addition of a considerable amount of sodium chloride resulted in a separation of layers. Phases were then separated and independently acidified. Each acidified product was extracted with ether and the extract stripped. The two products were characterized as follows:

* Dark brown.

2 Gray.

3 Mixture of mono-, di-, t-riand higher polyhasic acids and unsap. 4 Monohasic acids and unsap.

5 Di-, tri-, and higher polybasic acids.

The middle phases shown in Tables VII, VIII, IX, X and XI are examples of monocarboxylic acids useful as stabilizers in accordance with this invention.

THE COMPLEX ESTER STABILIZERS The monomeric esters of the complex carboxylic acid fractions are prepared by subjecting the acids to esterification with a stoichiometric amount of a monohydric alcohol having 1 to 20 carbon atoms, as hereinafter defined, under known esterification conditions. This process is described in detail in copending application Ser. No. 822,992, wherein the esters are formed by reaction of the mixed complex carboxylic acids with a monohydroxyl- 13 organic compound, present in at least stoichiometric amounts, at temperatures from 100 to 250 F., and allowing sufficient time to withdraw the water vapor formed from the esterification. The following examples are illustrative.

EXAMPLE IX 500 g. of complex acids (Sap. No. 221; avg. mol. wt. 630) resulting from the treatment of a solvent extract with sodium at 30 C. in the presence of tetrahydrofuran as the reaction solvent and carbonation at the same temperature, and which had been stripped of solvent, water-washed and acidified, were reacted with 370 g. of n-butanol, under reflux, while withdrawing water vapor until 35 g. of water was removed. The excess butanol was distilled off, producing a brown, fluid residue of the monomeric butyl ester which is non-volatile at 180 C. at 2 mm. Hg pressure. Other examples of esters that can be used in accordance with this invention are the stearyl, phenol, naphthyl, beta-naphthyl and methyl esters de scribed in application Ser. No. 822,922.

EXAMPLE X Another example is the preparation of the butyl ester of complex acid No. 101 of Table III, by reaction of 30 g. of the mixed mono-, di-acid with 150 ml. of n-butanol in the presence of 0.5 g. of p-toluene sulfonic acid at reflux temperature (118 C.) for 18 hours. The reaction mixture was diluted with ether and water-washed to free same of catalyst. The catalyst-free ether solution was distilled to remove the solvent and unreacted butanol, leaving the butyl ester as the residue.

Another example is the product produced by the foregoing method using the acid fraction No. 5 shown in Table VII. Also the various monocarboxylic acids shown in Tables VII through XI can be similarly esterified.

From the foregoing examples it is apparent that the stabilizing agents of this invention are defined by the formula wherein R is the complex nuclei of solvent extracts, FCC recycle stock or hydrogenated solvent extracts, n has a value of l to 2 and preferably 1, R is a member of the group of hydrogen and hydrocarbon radicals having 1 to 20 carbon atoms illustrated by methyl, ethyl, propyl, butyl, t-butyl, isobutyl, amyl, isoamyl, hexyl, heptyl, octyl, nonyl, dodecyl, tridecyl, up to octadecyl and eicosyl radicals, in the alphatic series, cycloaliphatic radicals such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl aromatic radicals having 6 to 10 carbon atoms, i.e., phenyl and naphthyl radicals, alkyl aromatic radicals comprising combinations of the aforementioned alkyl or cycloalkyl and the aryl radicals, aralkyl combinations of the same, and the like. A preferred sub-genus of esters and acids are those wherein n has a value of 1 and R is C -C aliphatic; and wherein n is l and R is hydrogen, and the latter representing the predominantly monobasic acid fraction.

Thus the esters are formed from such alcohols as methyl, ethyl, propyl, butyl, amyl, hexyl, octyl, n-decyl, lauryl, myristyl, cetyl and stearyl alcohols and cyclohexanol, benzyl alcohol, phenol, naphthol, cresols, methyl naphthols, ethyl naphthols, benzhydrol, triphenyl car binol, xylenols, monoethanolamine, diethanolamine, triethanolamine, aryl alcohol. The esterification reaction proceeds more readily with primary alcohols and is slower with secondary alcohols and tertiary alcohols.

The acids and their esters are further defined by the process of preparing same and their chemical characteristics, i.e., mol. wt., sulfur content and aromaticity.

Without limiting the invention, the characteristics of the products of this invention as influenced by the complex acids and their esters are further disclosed as thus far evaluated. In one aspect, the mono-, and a small amount of a dicarboxylic acid used are mixtures of acids of the dihydronaphthalene, dihydrophenanthrene, and dihydroanthracene types, averaging in molecular weight from about 375 to 450 and as high as 750, having several alkyl and/or cycloalkyl groups in each aromatic nucleus wherein the sum of the carbon atoms in the alkyl substituents varies between 5 and 22, and having acid numbers of to 200 and preferably 100 to 180. Despite the size of the acid molecules, the linkages through or between the carboxyl groups are about the same as those of phthalic and terephthalic acids. Some of the aromatic rings or condensed aromatic rings are probably further condensed with naphthenic rings to form configurations similar to the steroid ring system. Complex carboxylic acids from solvent extracts, obtained in the production of bright stocks, probably contain more highly condensed aromatic structures. Most of the sulfur (1.9 to 3.2% or 4.5% total sulfur being present) is in the form of heterocyclicrings with carbon, associated with both the aro matic-type and naphthenic-type structures present. Only trace amounts of the sulfur are present as high-molecularweight aliphatic sulfides. The nitrogen content of distilled solvent extracts is 0.01 to 0.04%. Analysis for the types of carbon linkages as percent C (carbon atoms in aromatic configuration) and percent C (carbon atoms in naphthenic configuration), gives results ranging from about 30-40% C 2035% C and 31-47% C using the method of Kurtz, King, Stout, Partikan and Skrabek (Anal. Chem. 28, 1928 (1956)). The complex monocarboxylic acids used in accordance with this invention have the following typical properties: acid numbers (1948 method) of from -200; M.P. 80-90 C.; Br. No. 4-24; sulfur 1.0-2.3%; are deep red in color, transparent in thin sheets, and contain 26% unsaponifiables. They are soluble in ethylether, acetone, methylethyl ketone, tetrahydrofuran, benzene, toluene and xylene. In order to demonstrate the stabilizing effect of these complex acids and their esters the following experiments are described.

EXAMPLE XI Fifty grams of polybasic acids (No. 1 01 in Table III, AN. 168; mol. wt. 405; percent unsaponifiable, 9) were dissolved in a mixture of 20 ml. benzene and 200 ml. n-pentane. The solution was cooled to 50 C. and filtered quickly. The filtrate was vacuum stripped and the resulting acid (MBA) had an A.N. of 137. The DDT used was a technical grade DDT that had been recrystallized from acetone.

A saturated DDT-kerosine solution was prepared at room temperature and contained 8% wt. DDT. The kerosine used for the preparation of the DDT solution had the following properties:

TABLE XII Boiling range, F. 351-530 Flash point, F. 139 Kauri-butanol No. 25 Aniline No., F 151.2 Refractive Index, 20 C 1.4500 API gravity, 60 F 43.5 Color (NPA) +27 This solution was divided into several fractions, and different amounts of the monocarboxylic acid fraction (MBA) were added to the samples. To another series of DDT solutions, an acid identified as E (a dimer acid and a proprietary product) was added to illustrate a prior art stabilizer. After the stabilizers were completely dissolved, 4 ml. of each of the samples was put into small test tubes (I.D.=1l mm). Each sample was seeded with a crystal of DDT and placed into a freezer, where the temperature was kept at 21 :L-l C. The samples were periodically checked, and as soon as enough material had crystallized out, the test tubes were centrifuged at each inspection for 3 minutes to determine the amount precipitated in millimeters. The results are given in the following table:

TABLE XIII hours, as in sample numbers 2 and 3 of Table XIII, sufficient protection is provided to assure stable concentrates under normal shipping, handling and storage conditions.

Stab. COIN Amount crystallized (mun) after hours- Stabilizer percent) 2.5 4.5

Sample No.:

1 None Trace...

.5 Clear-.- do

HO OOQQmQQOO 6... Trace.-- 3...

l The n-butylester of MBA was prepared by a conventional esterification method using n-butyl alcohol and the above MBA as in Example X.

The foregoing examples illustrate that small amounts of the complex acids or esters thereof have the ability of retarding, if not eliminating, the precipitation of DDT from hydrocarbon solutions. Additional illustrative compositions are:

TABLE XIV Toxicant Composition (Wt. percent) Ingredient 1 2 3 4 5 6 MBA Propyl ester of MBA. Phenyl ester of MBA- Naphthyl ester of MB Oetyl ester of MBA..- Stearyl ester of MBA A wide variety of petroleum solvents or hydrocarbon solvents can be used as the vehicle of the compositions of this invention. The solubility of the toxicants increases with increased cyclic nature and aromaticity of the solvent, as does the phytotoxicity, skin irritation and expense. In using predominantly aliphatic hydrocarbons as the vehicle, it is essential for purposes of the solubility of the toxicant therein that the solvent contain at least about 15% by volume of aromatic or cyclic compounds such as benzene, toluene, the xylenes, dimethylbenzenes, trimethyl benzenes, ethylbenzene, monomethylnaphthalenes, dimethylnaphthalenes, trimethylnaphthalenes, tetramethylnaphthalenes, ethylnaphthalenes, pine oil, terpenic hydrocarbons, cycloaliphatic compounds such as cyclopentane, cyclobutane, methylcyclo-pentane, dimethylcyclopentane, ethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane and related compounds.

The aliphatic portion of the solvent contains liquid aliphatic hydrocarbons such as pentane, hexane, isopentane, isohexane, heptane, octane and nonane and naphthas, Stoddard solvent, kerosene, gas, oil, alklates and related hydrocarbon mixtures, all of which boil in the range of about 170 F. to 760 F. One preferred species of solvent is deodorized kerosene, a neutral, inert white oil usually consisting of alkylated cycloparafiins and a small amount of paraflins. Deodorized kerosene is usually prepared by action of fuming sufuric acid on a kerosene distillate fraction at about 90 to 160 F., followed by neutralization with soda, water washing and filtration through an adsorbent clay.

The temperature (--21 C.) at which the tests reported herein were run is sufficiently low to assure that when only a trace of precipitate appeared at the end of 4 /2 Accordingly, the compositions of this invention meet the objective of stabilizing the toxicant against precipitation from concentrated solutions at low temperature, that is, the length of time that the toxicant solution may be subjected to temperatures low enough to cause it to be saturated or supersaturated without separation of the toxicant is greatly increaesd. Furthermore, when such crystals finally separate from the compositions of this invention, they are formed in small quantities only, remain suspended in the solution, and quickly redissolve when the toxicant mixture is warmed to ordinary room temperature, or about 70 F.

Through a study of the physical and chemical proper ties of the acids and esters described herein a representative structure of monocarboxylic acid fraction is:

HHH CH HHCOOH H H \l H 1 11 l l 1 Hot. H

CHaCHz H H t H tH, anti H wherein Het. represents a heterocyclic ring of S, N or O and the hydrogen of the carboxyl group can be replaced with R as herein defined.

The embodiments of this invention in which an exclusive property or privilege is claimed are defined as follows:

1. A stabilized composition comprising from about 20 to about weight percent of a liquid aliphatic hydrocarbon solvent boiling in the range of from about to about 760 R, an effective concentration of a halogenated hydrocarbon, insecticide, herbicide, fungicide or germicide, and a stabilizing amount of a compound selected from the group consisting of complex acids and the monomeric esters and partial monomeric esters thereof wherein:

(1) said complex acids are produced by subjecting to metalation complex aromatic compounds having an average molecular weight from 320 to 750, and being selected from the group consisting of:

(a) solvent extracts obtained in the solvent extraction of mineral lubricating oils using a solvent selective for aromatic compounds;

(b) the refined extracts obtained by hydrogenating, dewaxing and clay-contacting of the solvent extracts of (a); and

(c) the recycle stock obtained from fluid catalytic cracking of mineral oils; thereby forming the alkali metal adduct of said complex aromatic compounds; subjecting said adduct to carbonation to form the corresponding alkali metal carboxylates of said compounds; subjecting said carboxylates to acidification to form the free 17 carboxylic acid thereof and fractionation of said free acid to recover said complex acid containing no less than 80 weight percent of monocarboxylic acids and having an acid number no greater than about 200;

(2) said monomeric ester of said complex acid is pro duced by reaction of said acid with a stoichiometric amount of a monohydric alcohol having 1 to 20 carbons under esterification conditions at a temperature from about 100 to 250 F.; and

(3) said partial esters of said complex acid are produced by reaction under esterfication conditions of said complex acid with less than a stoichiometric amount of said monohydric alchol.

2. A composition of claim 1 wherein the concentration of said halogenated hydrocarbon is sufficient to saturate the solution comprising said aliphatic hydrocarbon solvent and said stabilizer.

3. A composition of claim 1 wherein said aliphatic hydrocarbon solvent is selected from the group consisting of kerosene, deodorized kerosene, gasoline, naphtha, Stoddard solvent, pentane, hexane, isopentane, isohexane, heptane, octane, nonane and gas oil.

4. The composition of claim 1 wherein said stabilizer comprises a compound derived from solvent extracts obtained in the solvent extraction of mineral lubricating oils using a solvent selective for aromatic compounds, and said extracts are characterized by having an average of about 1.7 to 3.5 aromatic nuclei per molecule, a sulfur content of 1.9 to 4.5 weight percent, a molecular weight of 320-750, and an API gravity of 7.3 to 18.3.

5. The composition of claim 1 wherein said halogenated hydrocarbon is selected from the group consisting of (his- (methoxyphenyl)trichloroethane) dichlorodiphenyldichloroethane, benzenehexachloride, 1,2,4,5,6,7,8-octachloro-4,- 7-methano-3a, 4,7,7a-tetrahydroindane, polychlorobicyclicterpenes, the gamma isomer of 1,2,3,4,5,6-hexachlorocyclohexane, 1,2,3,4,10,10-hexachloro 1,4,4a-5,8,8a-hexahydro-l,4,5,S-dimethanenaphthalene, 1,2,3,4,10,10 hexachloro 6,7 epoxy-1,4,4a,5,6,7,8,8a octahydro-1,4,5,8- dimethanenaphthalene, 1,1,1-trichloro 2,2 bis(p-methoxyphenyl)ethane, (2,4-dichlorophenoxy) acetic acid and esters and salts thereof, (2,4,5-trichlorophenoxy) acetic acid and esters and salts thereof, N-(trichloromethylmercapto)phthalimide, bis(dimethylthiocarbonyl)disulfide, pentachlorophenol, and cetyl trimethyl ammonium bromide.

6. The composition of claim 1 wherein said halogenated hydrocarbon is dichlorodiphenyltrichloroethane.

References Cited UNITED STATES PATENTS 2,490,437 12/ 1949 Hillyer. 3,153,087 lO/1964 Kramer et a1 260-327 3,277,014 10/1966 100 et al 252356 ALBERT T. MEYERS, Primary Examiner V. D. TURNER, Assistant Examiner US. Cl. X.R. 

